A wireless computing network typically comprises one or more wireless access points and one or more wireless clients. The access points might be physically connected to a standard wired network and might transmit data from the network over short distances via radio frequency signals. The clients may be, for example, but are not limited to, laptop computers. A reception device within a client receives a signal from an access point, converts the signal to digital data, and delivers the data to the client. Thus, the radio frequency signals are used to provide data much as the data cables in wired networks.
As wireless networks, such as those specified in the IEEE 802.11 family of standards, become more prevalent, the amount of power consumed by the devices used in such networks can become a concern. Among the factors that can affect the power consumption of wireless reception devices are biasing, phase noise, filtering, and the analog-to-digital data conversion process.
Biasing refers to a current or voltage used within an electronic circuit in order to allow the active devices within that circuit to perform their desired functions. The greater the amount of biasing used in a circuit, the more power the circuit typically uses. Phase noise refers to any random time distortions within a signal that is intended to be periodic. More power is typically required when less phase noise is desired in a device. Filters are used in some devices to block unwanted adjacent signals. Wireless communication standards typically define the maximum signal power allowed unwanted adjacent interfering channels. Generally, the more filters that are used by a device, the more power that is required by that device.
In analog-to-digital conversion, a particular number of digital bits are typically needed to represent a particular analog signal. The greater the data transmission rate of the signal and the more interference there is in the signal due to undesired adjacent signals relative to the strengths of the desired signal, the greater the number of bits that are needed. A greater amount of power is needed for a large number of bits than for small number of bits.